Preheater and reducer for electric smelting-furnaces.



A STANSFIELD.

PR BHEATER AND REDUCBR FOR, IiLECTRIG SMELTING FURNACES. APPLIOATIOH FILED 11017.11, 1909.

2 SHEETSSHEET l.

r 984,308. Patented Feb. 14, 1911.

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A. STANSFIELD.

PREHEATER AND REDUOBR FOR ELECTRIC SMELTING' FURNACES. I APPLICATION FILED N037. 11. 1909. 984,308.

Patented Feb. 14, 1911.

2 SHEETS-SHEET 2.

wiimwoe-o UNITED STATES PATENT OFFICE.

ALFRED STANSFIELD, OF MONTREAL, QUEBEC, CANADA, ASSIGNOR OF ONE-HALF TO JOHN W. EVANS, OF BELLEVILLE, CANADA.

PREHEATER AND REDUCER FOR ELECTRIC SMELTING-FURNACES.

laga, Province of Quebec, and Dominion of Canada, have invented certain new and useful Improw ements in Preheaters and Re ducers for Electric Smelting-liurnaces, of which the following is a specification.

The object of my invention is to provide improved means for preheating and partially reducing ores. and particularly iron ores, for final reduction in a suitable furnace, such as an electric smelting furnace,

' and to this end I utilize the hot gases arising from the ores being smelted in the furnace for preheating the ores fed to .such furnace.

My invention comprises the novel details of improvement and combinations of parts that will be more fully hereinafter set forth and then pointed out in the claims.

Reference is to be had to the accompanying drawings forming part hereof, wherein,

Figure 1 is a vertical section of an appartus embodying my invention, the same being adapted for the production of steel; Fig. 2 is a section on the line 2, 2, in Fig. 1.; Fig. 3 is a. section on the line 3, 3, in Fig. 1; Fig. 4 is a cross section on the line 4 4, in Fig. 1; Fig. 5 is a sectional detail of an ore pusher, and Fig. 6 is a vertical section of a furnace adapted for the production of pig iron. 1

At 1 is a suitable furnace, shown in Figs. 1 and 4 as provided with a removable roof 1 to enable ready relining of the fur naee, the latter being provided with suitable doors, tapping holes etc, all of which may be of any well known construction. At 2 are horizontally disposed electrodes entering chamber 1 of the furnace, and at 3 are vertical electrodes entering said chamber, which electrodes may be protected in any suitable manner at the walls of the furnace, and may be operated by any suitable means. At 4 is a chamber communicating with chamber 1 of the furnace. In Figs. 1 to 4 l have shown a chute or passage'o communieating with the bottomv of chamber 4 and X with chamber 1". At 6' is a combustion space within which one or more pipes 7 are located, whichpipes may be of metal, brick or other suitable material and at their lower ends communicate with chamber 4, as

Specification of Letters Patent.

Application filed November 11, 1909. Serial No. 527,423.

Patented Feb. 14, 1911.

a suitable number of holes 7 in their walls through which gases from heated ore in said pipes may pass into space 6. Pipes 7 are provided with suitable charging devices 8 at their upper ends arranged to maintain said pipes closed during operation. The walls of combustion space 6 are shown provided with holes 9 for the admission of air to support combustion of gases in said chamber. Chute 5 is shown provided with a damper or valve .10 which is adapted to close the chute to prevent the entrance of air into chamber 4 and pipes 7 when the furnace chamber 1 is opened. At 11 are pushers shown leading through the wall of chamber 4 in line with chute 5 to aid in pushing ore from chamber 4 through said chute into the furnace-chamber 1 Pushers 11 may be mainly of iron, and may be protected from the heat-by having their inner ends provided with blocks 11 of fire clay or the like, and pushers 11 may be hollow to receive water for coolingthem (see Fig. 5). Pushers 11 may be worked through suitable stuffing boxes to prevent the escape of gases or the entrance of air. Said pushers may be withdrawn into the walls of the furnace between charging times to escape the heat from the ore. Said pushers may be operated in any suitable manner. as by cranks 12. The products of combustion from space 6 may pass through a suitable fine 13 into a chimney 14.

The furnace above described is adapted for the production of steel direct from iron ore. The ores or briquets descend from pipes 7 7 to the desired extent and the pipes closed by the chargingdevice 8, and in Starting the furnace a charge is also placed in furnace chamberl The iron ore is mixed with some reducing agent. such as charcoal, and with some suitable flux, such as limestone, unless' the ore is self fluxing. mixture should be sufliciently coarse to per- ,jmit the passage of gases through it within pipes 7, but if the ore or mixture is too fine for this purpose the same may be briqueted. The ores to be treated are charged into pipes into chamber 4. and are pushed into chute .7, as required, by pushers. 11; During the 1 operation hot reducing gases are generated The ore or in the furnace chamber 1", as the ore therein is melted by heatfrom the electric arc, and such hot gases pass up chute 5, through the ore or mixture in chamber l, thus serving to heat. the same and in part; reduce the ore therein to the metallic state. The gases then pass upwardly through the openings st in the roof of chamber i into spaci they burn. and the ore or n'iixture in pipes 7 also gi es ofl combustible gases by reason of the heat in space (3, which gases pass through the openings 7 into space 6 where they burn. In this manner space 6 is kept at a high heat, pipes T and the ore or ore mixture therein are highl heated, and the ore or mixture is partly reduced to metal before itenters the furnace chamber 1 The ore or mixture from pipes 7 in their descent are maintained heated, so that the ore enters the furnace chamber 1 in a partiall) reduced state thereby aiding in the final reduction of the ore in said chamber, by the heat from the clcctr'". are at the horimintal electrodes and from the current flowing through the ore from the vertical electrodes, which dip into the ore, and by this means the heat generated at the arc is conserved and the efficiency of the apparatus is maintained. The charging devices enable the ore to be introduced into the furnace in small amounts at a time, until enough has been introduced,

and the charging may then be stopped until the furnaceis ready for a new charge, but

the ore in the tubes is being heated and reduced continuously.

' The form of apparatus illustrated in Fig. 6 is adapted for the production of pig iron. For this purpose I have shown chambcr -l above chamber 1 electrode 3 entering thelatter. The chute 5, damper l0 and ushers 11 are dispensed with as the pipes 4 and chambers a and 1 are maintained charged with ore. for a. continuous supply. The same effect as before described is produced, viz: The heated gases rising, from the ore in chamber 1 pass through the ore in chamber l and exercise their reducing action upon the ore therein before passing. into space 6 and heating the ore in pipes 7. In this case chamber 4 may be regarded as or equivalent to the shaft of an ordinary electric furnace or blast furnace communicating with combustion space 6.

I do not broadly claim the arrangement of the electrodes in the furnace chamber 1 independently of the preheating and reducing devices.

Having now described my invention what. I claim is 1. The combination of a furnace, a chamber communicating therewith. a combustion space above said chamber, one or more pipes in said combustionepace to receive ore and .pro\ ided with opening coinmunicatin; with said space. and means to admit air; into said i where i space to support combustion therein of gases passing from the openings in said pipe into said space.

2. The combination of a furnace, a chamber at one sidethereof, an inclined chute connecting the chamber and the furnace, a combustion space above said chamber, and pipes in said space comn iunicating with said chamber and said space.

1. The con'ibination o 1' a furnace, a cham her at one side of the furnace to permit access to the latter, an inclined chute connecting the chamber and the furnace, a combustion space above said chamber, perforated pipes in said space communicating with the first named chamber and with said combustion space, means to permit the escape of gases from the pipes into said space, and means to admit air to said space around said pipes.

i. The combinationof a furnace. a chamher, an inclined chute connecting the chamher a n d the furnace, a combustion space above said chamber, pipes in said space communicating with said chamber, means to permit the escape of gases from the pipes into said space, and a pusher below said chamber to push material therefrom into the furnace.

5. The combination of a furnace, a chamher, an inclined chute connecting the chamber and the furnace, a combustion space above the said chamber, pipes in the combustion space communicating with said chamber. means to permit the escape .of gases from the pipes into said space, and a door or damper to close said chute.

6. The combination of a furnace, electrodes projecting therein, a chamber, an inclined chute connecting said chamber with the furnace. one or more perforated pipes connnunicating with said chamber, and perforated walls inclosing said pipes providing a combustion space around the pipes to support combustion in said space of gases cnterin; the same from said perforated pipes.

7. The combination of a furnace, electrodes projecting therein, a chamber, an inclined chute connecting said chamber with the furnace. one or more perforated pipes eennnunicating with said chamber, perforated walls inclosing said pipes providing a. combustion space around the pipes, and means to support combustion in said space, said pipes having openings communicating with said space.

S. In an ore preheater and reducer, the combination of a furnace, a combustion space communicating therewith, one or more perforated pipes in said space communicating with the furnace and said space,

means to admit ore to said pipes and retain reducing gases therein, and means to intermittently supply ore from said pipes to the furnace while the ore in said pipes remains hot and surrounded by hot reducing gases.

9. The combination of a furnace, at chamber communicating with the furnace and having an arched roof, a combustion space containing perforated pipes opening through said roof into said chamber, .said space and chamber being located at one side of said furnace.

10. The combination of a furnace, a chamber communicating with the furnace, perforated pipes communicating with said chamber, a combustion space containing said pipes and provided with air admission holes, said chamber and space being located atone side of the furnace,'and electrodes entering the furnace at one side of said chamber and space.

Signed at Montreal in the county of Hochelaga and Dominion of Canada, this 8th day of November, A. D. 1909.

ALFRED STANSFIELD.

Witnesses:

FRED J. STARR, 'ARTHUR H. Evans. 

